A basis for rigorous versatile learning is introduced theoretically, that i
s the framework of fuzzy lattices or framework for short, which proposes a
synergetic combination of fuzzy set theory and lattice theory. A fuzzy latt
ice emanates from a conventional mathematical lattice by fuzzifying the inc
lusion order relation. Learning in the FL-framework can be effected by hand
ling families of intervals, where an interval is treated as a single entity
/block the way explained here. Illustrations are provided in a lattice defi
ned on the unit-hypercube where a lattice interval corresponds to a convent
ional hyperbox, A specific scheme for learning by clustering is presented,
namely sigma-fuzzy lattice learning scheme or sigma-FLL (scheme) for short,
inspired from the adaptive resonance theory (ART), Learning by the sigma-F
LL is driven by an inclusion measure a of the corresponding Cartesian produ
ct to be introduced here. We delineate a comparison of the sigma-FLL scheme
with various neural-fuzzy and other models. Applications are shown to one
medical data set and two benchmark data sets, where sigma-FLL's capacity fo
r treating efficiently real numbers as well as lattice-ordered symbols sepa
rately or jointly is demonstrated. Due to its efficiency and wide scope of
applicability the sigma-FLL scheme emerges as a promising learning scheme.